<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2019/03/21
  Time: 15:08
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>websocket</title>
</head>
<body>
222222
<h3 id="message"></h3>
</body>
<script type="text/javascript">
    var websocket = null;
    var username = "portal";
    var messageServerPath_ws = "localhost:8001/ta3message";
    //判断当前浏览器是否支持WebSocket
    if ('WebSocket' in window) {
        websocket = new WebSocket("ws://" + messageServerPath_ws + "/jwebsocket.do");
    } else if ('MozWebSocket' in window) {
        websocket = new MozWebSocket("ws://" + messageServerPath_ws + "/jwebsocket.do");
    } else {
        alert('当前浏览器 Not support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function () {
        setMessageInnerHTML("WebSocket连接发生错误");
    };

    //连接成功建立的回调方法
    websocket.onopen = function () {
        setMessageInnerHTML("WebSocket连接成功");
        websocket.send(username);
    }

    //接收到消息的回调方法
    websocket.onmessage = function (event) {
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function () {
        setMessageInnerHTML("WebSocket连接关闭");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function () {
        closeWebSocket();
    }

    //关闭WebSocket连接
    function closeWebSocket() {
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

</script>
</html>
